Sheaves



Sept 17 1957 E. J. MecLosKEY ETAL 2,806,381

SHEAVES 2 Sheets-Sheel l Filed June 18, 1956 I inni-1.555555!!! BY Jap. Z526@ v l ATTORNEYS 7 Sept 17, 1957 E. J. MccLsKEY ET AL 2,806,381

- sHEAvEs Y med June 12s,l 195e 2 sheets-sheet 2 ATORNEYS 2,806,381 Patented Sept. 17, 1957 tice SHEAVES Ellsworth J. McCloskey, Norristown, Pa., and .lames E. Williams, Charlotte, N. C., assignors to The American Pulley Company, Philadelphia, Pa., a corporation of Pennsylvania Application June 18, 1956, Serial No. 592,183 6 Claims. (Cl. 711-230.17)

This invention relates to sheaves. More particularly, it is concerned with sheaves intended for use with V belts, and of which the belt engaging flange disks are laterally adjustable for the purposes of speed changing.

In connection with sheaves of the kind referred to. I aim to provide improved means whereby the liange disks can be adjusted toward or away from each other relative to the central transverse plane of a supporting hub sleeve without causing lateral shifting of the engaged belt, as well as improved reliable means for locking the flanges in adjusted positions against the possibility of displacement during the use of the sheave.

Another object of my invention is to secure the above advantages in an adjustable sheave which is of simple and compact construction and which can be produced in quantity at small cost.

Other objects and attendant advantages will appear from the following detailed description of the attached drawings, wherein:

Fig. l is a staggered axial sectional view of an adjustable sheave conveniently embodying our invention, the section being taken as indicated by the angled arrows I-I in Fig. 2.

Fig. 2 is a fragmentary elevational view of the sheave as viewed from the left of Fig. l.

Fig. 3 is a fragmentary elevational view of the sheave as viewed from the right of Fig. 1.

Fig, 4 is a View corresponding to Fig. l showing the sheave differently adjusted.

Figs. 5 and 6 are fragmentary views in cross section taken as indicated respectively by the angled arrows V-V and VI--VI in Fig. 4; and

Figs. 7, 8, 9 and 10 are perspective views of various parts of the sheave hereinafter more particularly referred to.

As herein exemplified, the improved sheave of our invention comprises a pair of opposingly bevel-faced beltengaging ange disks 1 and 2 which are axially adjustable toward or away from each other on a sleeve 3 split longitudinally as at 4. The outer face of the sleeve 3 is cylindrical and of a diameter corresponding to the axial openings in the surrounding flange disks 1 and 2. The sleeve 3 is taperingly bored inwardly from opposite ends as at 5 and 6, the taper at 5 being more abrupt than the taper at 6 and its depth, i. e. linear extent, being approximately one third that of the latter, as best seen in Fig. 7. Engaging into the opposite ends of the hub sleeve 3 and surrounding the shaft 7 upon which the sheave is mounted, are correspondingly tapered long and short wedge bushings 3 and 9 which are separately illustrated in Figs. 8 and 9. As shown, in Figs. 1-4, the diameter of the bore in the short bushing 8 is slightly larger than the diameter of the shaft 7, while the bore in the longer bushing 9 corresponds exactly to that of said shaft so as to lit snugly thereupon. `For a purpose presently explained, the bushings 8 and 9 are formed in their outer surfaces with longitudinally-extending square section grooves 16 and l1 of which the bottoms are parallel with the bushing axes. At the small end of the bushing 9 the groove 11 is widened as at 11a and said bushing is split centrally of the grooves as at 12. The bushings 8 and 9 also respectively have key ways 13 and 14 in their bores, diametrically opposite the grooves 10 and 11, for engagement by a spline 7a on the shaft 7.

The means provided for laterally adjusting the flange disks 1 and 2 laterally toward or away from each other includes a screw element 15 having a central collar 16 thereon which engages into transverse notches 17 cut into opposite sides of the split 4 of the sleeve 3 medially of the length of the latter, and is cleared in the widened portion 11a of the groove 11 in the bushing 9. The opposite end portions of the screw element 15 are reversely threaded and respectively engage into correspondingly threaded holes in lugs 18 and 19 (one of these being illustrated in perspective in Fig. l0) which are secured by cap screws 20 and 21 to the outer sides or the flange disks 1 and 2. As shown, the lugs 18 and 19 have square section portions which project through the split 4 of the sleeve 3 into the grooves 1t) and 11 of the bushings 8 and 9, and anchorage ears which are recessed laterally into the flange disks 1 and 2, and of which. the holes for screws 20 and 21 are counterbored or recessed to receive the screw heads. At one end, the adjusting screw element 15 is provided with a polygonal head 25 for convenience of wrench application in making adjustments.

The means provided for fixing the position of flange disks l and 2 after adjustment includes a pair of locking screw elements 30 which, respectively, are arranged in quadrant relation to the adjusting screw element 1S, and which are freely rotatable in apertures 3.1 in the wedge bushing 8 but constrained against axial displacement by a polygonal head 32 and a stop collar 33 thereon respectively in abutment with the opposite ends of said bushing, the distal end of said screw element threadedly engaging into tapped holes in the bushing 9. It will be noted that the sleeve 3 is cut away as at 34 at diametrically opposite points to clear the collars 33 of the screw elements 30.

In Fig. l, the ange disks 1 and 2 are in direct contact, and the wedge bushings 8 and 9 are drawn toward each other to the fullest extent by the locking screw elements 3l?, with the split sleeve 3 circumferentially expanded by the wedging action of the bushings within the axial openings of said flange disks to lix the latter in position. ln this connection it wil be observed that the ange disks 1 and 2 are held against rotation relative to the sleeve 3 through engagement of the lug elements 13 and 19 within the grooves 1i) and 11 of the wedge bushings 8 and 9. For further assurance against such relative rotation, the flange disks 1 and 2 and the sleeve 3 are provided with complemental grooves 35 and 36 for the key indicated at 37.

To adjust the sheave, the locking screw elements 30 are first backed olf with the result that the wedge bushing 9 is moved axially relative to the wedge bushing 8, thereby permitting the split sleeve 3 to contract for relief of the flange disks 1 and 2. With this accomplished, the adjusting screw element 15 is turned in the proper direction so that, by the action of reversely pitched threads at the opposite ends thereof upon the lugsv18 and 19, the flange disks 1 and 2 are gradually moved apart, the full extent of such movement being shown in Fig. 4. During the adjustment, the adjusting screw element l5 is prevented from shifting axially relative to the wedge bushing 9 due to the engagement of the collar lo on said screw element within the notches 17 of said bushing and the ilange disks are maintained centered between the ends of the bushing. When the flange disks 1 and 2 have been separated to the desired extent, the locking screw elements are .re-tightened with attendant drawing of the bushing 9 toward the bushing 8 and circumferential expansion of thev sleeve 3- within the axial openings of the ange disks'l and 2 to lock the latter againstaccidental displacement in adjusted position.

Having thus described our invention, we claim:

l. In adjustable s-heave,apairiof opposingl'y-tapcred bushings axially bored te engage about a shaft whereon the sheave is mounted; a surrounding longitudinally-split hub sleeveA having a cylindrical outer surface and taperingly bored inwardly` from opposite ends to correspon-dwith the tapering of the respective bushings; a pair of opposingly-beveled annular bel`t-engaging ange disks in turn surrounding the sleeve with capacity to be shifted therealong; inwardly projecting lugs on the respective disks extending through the split of the sleeve and respectively engagingV intolongitudinal grooves in the outer surfaces of the two bushings; andren adjusting screw element with oppositely pitched threaded end portions engaged in correspondingly tapped apertures in the lugs on the respective disks, said screw having a medial collar constrained within lateral conning recesses respectively in opposite sides of the split in the sleeve.

2. An adjustable sheave according to claim 1, further including a spline for preventing rotation of the bushings relative to the shaft, and a spline for preventing rotation of the flange disks relativeto the sleeve.

3, An adjustable sheave, according to claim 1, wherein 4 the bushings differ in length and in taper, and wherein the ends of the sleeve are taperingly bored to correspond with the tapering of the respective bushings.

4. An adjustable sheave according to claim 1, wherein the lugs are recessed into the outer faces of the respective flange disks and secured by cap screws whereof the heads are recessed into said lugs.

5. An adjustable sheave according to claim 1, further including at least one locking. screw element annularly spaced from the adjusting screw element, said locking screw element constrained to rotation inone of the bush ings and threadedly engaged i-n the other bushing.

6. An adjustable sheave according to claim 1, wherein the bushings differ in length and in taper, and' wherein the ends of the sleeve are taperingly bored to correspond with the tapering of the respective bushings, further including at least one locking screw element annularly spaced from the adjusting screw element, said locking screw element being constrained to rotation in the short bushing and threadedly engagedv in the longer bushing.

References Cited in the file of this patent UNITED STATES' PATENTS 2,610,515 Williams Sept. 16, 1952 2,696,997 McCloskey Dec. 14, 1.954 2,717,519 Kooistra Sept. 13, 1955 

